This guy built a frame just using blocks, and the frame design printout. He is an engineer, though, so he's probably used to doing highly detailed work.

There is no such thing as successfully building without a jig. No matter what you call it, you have to hold the tubes somehow in the position you created to braze them together. Probably if you are doing it simply (as already suggested), you have Paragon's aluminum blocks holding the tubes sitting on top of a full scale drawing. That works but isn't how I would do it. The Brits taught me how they typically did it 50 years ago when I was learning over there. Movable flat pieces representing the tubes in the front triangle are held a rectangular "picture frame". The 4 flat pieces replace the need to do a full scale drawing and can be easily moved to refine your frame design as you study it as you create it. .My first one came from Johnny Berry's shop in Manchester, England. I've refined it many times since. Here is an example made by Tim one of my students in the 80's that I took over to Ukraine because i easily get it over there in a bike box.

https://cimg4.ibsrv.net/gimg/bikefor...1183b4f913.jpg
This simple jig was made on my vertical mill out of cold rolled steel by one of my students 40 years ago.

Now I use one with many more bells and whistles laser cut and etched out os stainless in Ukraine. I create the frame design based on a person's bicycle position refined on some kind of fitting bicycle. The fixture can hold their seat and handlebar in the same position and I slide the plate pieces representing the tubes to match. This better serves good recreational cyclists. The go fastest crowd are going to buy the latest carbon bike. The fixture itself sits on some kind of flat surface (in my case it is Johnny Berry's old cast iron flat table) to insure I'm able to maintain accurate alignment based off of the table's flat surface.

Here is one of my latest versions that has gone through many revisions over many years.
https://cimg5.ibsrv.net/gimg/bikefor...00fa1e141.jpeg
The fixture shows seat and head tube angles, tube lengths and has pieces that can set BB drop and fork rake without getting out rulers and protractors.

Back in the ‘90s you could order the Paterek manual from Henry James. It was a binder that held the paper which was a book on how to build a bike frame.



The instructions in his book for building a lugged frame did use some jigs. He had a jig for the front triangle and another separate jig for the rear triangle. His book is available as a free online PDF:

The-Paterek-Manual.pdf



But for building a fillet frame, he did not use a jig for the front triangle. That chapter is about 2/3 into the book.



Not wanting to invest in building or buying any jigs myself, I decided to follow his instructions to make a fillet frame. I started by making the headtube-downtube “hockey stick” junction freehand according to the manual. I remember making a very accurate miter and having and one tube perched on top of the other, weighted down and balanced. It stayed put during the tacking as I hoped it would. After that I was off to the races, and the rest of the bike was built in a similar ad hoc way.



My experience building this frame 27 years ago is still on my blog:

https://drewdevereux.wordpress.com/2...09/framebuild/

Real framebuilders will probably cringe reading that post, but the frame held up fine over lots of miles and it rode well. Today I build maybe one frame every few years (for myself) and still without formal jigs. I do use a full size drawing, flat table (or very flat piece of heavy plywood), straight edges, angles, string, etc. Each joint needs a way to hold the tubes in the right place. I just figure out ways to do that with stuff I can find in the garage. Norm Taylor relied on the glint of a bright line of light from the window outside to tell him his tubes were parallel. I do that too. There is an interesting youtube of the Taylor brothers and their framebuilding here:




It would be nice to have a frame and fork jig, but for me the jig would spend most of its time sitting around not being used. A frame jig would save lots of build time and make things easier, but I don’t think it would improve my accuracy because building freehand already does well in that regard for me.

Drew Devereux

Excellent post! I make TIG frames. To attach the CS to the BB I use blocks on the table with everything vertical). This is very accurate. Then I have a simple homemade jig for the front triangle. After watching that video (a few years ago) I also found that you can see whether the HT and ST are parallel better just by looking down them than with anything you can easily measure them with if you don't have an alignment table. Easily accurate enough for a frame that rides perfectly (although I will never criticise anyone pursuing greater perfection, because that is always a fine goal).

Really good fixturing saves time in a production environment. In a low volume hobbyist environment you can manage with much less.

I am enjoying this thread! Currently drawing the rear triangle to work out what CS to get. Also since I will be using an eccentric BB I am, in my mind, designing a jig to either cut or grind the CS to BB mitre.

I'm also finding this thread interesting. One question though. When building without a jig, how do you insure your bottom bracket centerline is perpendicular to the plane of the main triangle? Put another way, how close to perpendicular does it need to be?

BB to ST is the first joint I do. I set it up loosely with the BB in some angle iron on the table and the ST resting on a welding magnet. I get it square with a set-square and centered by checking a caliper depth gauge is the same both sides.

A couple of tacks, and then I check it by holding the side of the BB flat against the table and measuring the height between the table and the side of the tube at the end. That will magnify any tiny errors. I check that gap is the same both ways up (and using the same part of the table).

Any slight corrections necessary are then made (the tacks will bend a bit). Then when it's perfect I tack it evenly all the way around with about û tacks and then weld it.

I'll add that I use some kind of stationary fitting bike to assist with creating a frame design on my fixture. Recreational cyclists tend to sit a bit more upright and their position may not work as well on a typical road bike. One of my goals is to fit the frame to the rider and not the other way around. It isn't that hard to find a recreational fit. One doesn't need a fancy Retul or Serotta fit bike to do the job (although wonderful to have). I posted details of how to make one yourself. Once I find their seat/handlbar/BB relationionship, I recreate their position on my fixture and then slide the pieces that represent the frame tubes around to match.

https://cimg9.ibsrv.net/gimg/bikefor...ea1be80e7.jpeg
This is a fitting bike one can DIY

https://cimg5.ibsrv.net/gimg/bikefor...b44b2eb3d.jpeg
My center post can show top tube straddle height and the T tool at the top can indicate saddle setback. The T tool in the middle can level the top tube or adjust it to about any angle. Hex pieces made setting fork rake and BB drop easy.

The other feature I prefer is that I can easily adjust the frame design after I have created it. Having it life size in front of me makes it easer to see if everything looks proportional. That way I can assure I have the right head tube length to stem extension.

I'm a garage builder that has never used a jig. I do have a Blanchard ground hunk of steel, along with a bottom bracket post, so alignment can be verified at each step of the process. I also make a full size drawing of each frame, so progress can be compared to that as each tube is added. I also build with lugs, because they are the most forgiving build method (my opinion).

For example: Miter seat tube fit into BB shell. Pin together, and check alignment. Tack braze, quickly check alignment, align as needed, and finish braze work. Once cool, remove flux and back to an alignment check, and tweak as needed. Done. Move to next joint, and so it goes.

This is basically my memory from Doug's class. I only have my dad's old Craftsman table saw as a flat surface (big enough, at least with the cast iron extensions), but don't have a post.

That's how I did it 45 years ago. I enjoyed the few frames I built. I was going to georgetown during my building time and just miles from Proteus design where I got some builder tips. .I was told don't bother without a jig but I was in a career that had clearances of a couple thou so the bike was easy. My 1st frame is on my wahoo trainer and I'm still racking up the miles on it.